crypto: skcipher - remove remnants of internal IV generators

Remove dead code related to internal IV generators, which are no longer
used since they've been replaced with the "seqiv" and "echainiv"
templates.  The removed code includes:

- The "givcipher" (GIVCIPHER) algorithm type.  No algorithms are
  registered with this type anymore, so it's unneeded.

- The "const char *geniv" member of aead_alg, ablkcipher_alg, and
  blkcipher_alg.  A few algorithms still set this, but it isn't used
  anymore except to show via /proc/crypto and CRYPTO_MSG_GETALG.
  Just hardcode "<default>" or "<none>" in those cases.

- The 'skcipher_givcrypt_request' structure, which is never used.

Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

Documentation/crypto/api.rst

@@ -1,15 +1,6 @@
 Programming Interface
 =====================
 
-Please note that the kernel crypto API contains the AEAD givcrypt API
-(crypto_aead_giv\* and aead_givcrypt\* function calls in
-include/crypto/aead.h). This API is obsolete and will be removed in the
-future. To obtain the functionality of an AEAD cipher with internal IV
-generation, use the IV generator as a regular cipher. For example,
-rfc4106(gcm(aes)) is the AEAD cipher with external IV generation and
-seqniv(rfc4106(gcm(aes))) implies that the kernel crypto API generates
-the IV. Different IV generators are available.
-
 .. class:: toc-title
 
 	   Table of contents

Documentation/crypto/architecture.rst

@@ -157,10 +157,6 @@ applicable to a cipher, it is not displayed:
 
    -  rng for random number generator
 
-   -  givcipher for cipher with associated IV generator (see the geniv
-      entry below for the specification of the IV generator type used by
-      the cipher implementation)
-
    -  kpp for a Key-agreement Protocol Primitive (KPP) cipher such as
       an ECDH or DH implementation
 
@@ -174,16 +170,7 @@ applicable to a cipher, it is not displayed:
 
 -  digestsize: output size of the message digest
 
--  geniv: IV generation type:
-
-   -  eseqiv for encrypted sequence number based IV generation
-
-   -  seqiv for sequence number based IV generation
-
-   -  chainiv for chain iv generation
-
-   -  <builtin> is a marker that the cipher implements IV generation and
-      handling as it is specific to the given cipher
+-  geniv: IV generator (obsolete)
 
 Key Sizes
 ---------
@@ -218,10 +205,6 @@ the aforementioned cipher types:
 
 -  CRYPTO_ALG_TYPE_ABLKCIPHER Asynchronous multi-block cipher
 
--  CRYPTO_ALG_TYPE_GIVCIPHER Asynchronous multi-block cipher packed
-   together with an IV generator (see geniv field in the /proc/crypto
-   listing for the known IV generators)
-
 -  CRYPTO_ALG_TYPE_KPP Key-agreement Protocol Primitive (KPP) such as
    an ECDH or DH implementation
 
@@ -338,18 +321,14 @@ uses the API applicable to the cipher type specified for the block.
 
 The following call sequence is applicable when the IPSEC layer triggers
 an encryption operation with the esp_output function. During
-configuration, the administrator set up the use of rfc4106(gcm(aes)) as
-the cipher for ESP. The following call sequence is now depicted in the
-ASCII art above:
+configuration, the administrator set up the use of seqiv(rfc4106(gcm(aes)))
+as the cipher for ESP. The following call sequence is now depicted in
+the ASCII art above:
 
 1. esp_output() invokes crypto_aead_encrypt() to trigger an
    encryption operation of the AEAD cipher with IV generator.
 
-   In case of GCM, the SEQIV implementation is registered as GIVCIPHER
-   in crypto_rfc4106_alloc().
-
-   The SEQIV performs its operation to generate an IV where the core
-   function is seqiv_geniv().
+   The SEQIV generates the IV.
 
 2. Now, SEQIV uses the AEAD API function calls to invoke the associated
    AEAD cipher. In our case, during the instantiation of SEQIV, the